Wire sexp.js into page template with auto-init and HTMX integration

- Load sexp.js in ~app-layout before body.js
- Auto-process <script type="text/sexp"> tags on DOMContentLoaded
- Re-process after htmx:afterSwap for dynamic content
- Sexp.mount(target, expr, env) for rendering into DOM elements
- Sexp.processScripts() picks up data-components and data-mount tags
- client_components_tag() Python helper serializes Component objects
  back to sexp source for client-side consumption
- 37 parity tests all passing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sexp/jinja_bridge.py

@@ -201,6 +201,40 @@ def _get_request_context():
 # Quart integration
 # ---------------------------------------------------------------------------
 
+def client_components_tag(*names: str) -> str:
+    """Emit a <script type="text/sexp"> tag with component definitions.
+
+    Reads the source definitions from loaded .sexpr files and sends them
+    to the client so sexp.js can render them identically.
+
+    Usage in Python::
+
+        body_end_html = client_components_tag("test-filter-card", "test-row")
+
+    Or send all loaded components::
+
+        body_end_html = client_components_tag()
+    """
+    from .parser import serialize
+    parts = []
+    for key, val in _COMPONENT_ENV.items():
+        if not isinstance(val, Component):
+            continue
+        if names and val.name not in names and key.lstrip("~") not in names:
+            continue
+        # Reconstruct defcomp source from the Component object
+        param_strs = ["&key"] + list(val.params)
+        if val.has_children:
+            param_strs.extend(["&rest", "children"])
+        params_sexp = "(" + " ".join(param_strs) + ")"
+        body_sexp = serialize(val.body, pretty=True)
+        parts.append(f"(defcomp ~{val.name} {params_sexp} {body_sexp})")
+    if not parts:
+        return ""
+    source = "\n".join(parts)
+    return f'<script type="text/sexp" data-components>{source}</script>'
+
+
 def setup_sexp_bridge(app: Any) -> None:
     """Register s-expression helpers with a Quart app's Jinja environment.
 

shared/sexp/templates/layout.sexp

@@ -70,6 +70,7 @@
                     (when content-html (raw! content-html))
                     (div :class "pb-8"))))))
           (when body-end-html (raw! body-end-html))
+          (script :src (str asset-url "/scripts/sexp.js"))
           (script :src (str asset-url "/scripts/body.js")))))))
 
 (defcomp ~oob-response (&key oobs-html filter-html aside-html menu-html content-html)

shared/sexp/tests/test_sexp_js.py

@@ -133,6 +133,36 @@ class TestComponents:
         assert html == '<div><span>hi</span></div>'
 
 
+class TestClientComponentsTag:
+    """client_components_tag() generates valid sexp for JS consumption."""
+
+    def test_emits_script_tag(self):
+        from shared.sexp.jinja_bridge import client_components_tag, register_components, _COMPONENT_ENV
+        # Register a test component
+        register_components('(defcomp ~test-cct (&key label) (span label))')
+        try:
+            tag = client_components_tag("test-cct")
+            assert tag.startswith('<script type="text/sexp" data-components>')
+            assert tag.endswith('</script>')
+            assert "defcomp ~test-cct" in tag
+        finally:
+            _COMPONENT_ENV.pop("~test-cct", None)
+
+    def test_roundtrip_through_js(self):
+        """Component emitted by client_components_tag renders identically in JS."""
+        from shared.sexp.jinja_bridge import client_components_tag, register_components, _COMPONENT_ENV
+        register_components('(defcomp ~test-rt (&key title) (div :class "rt" title))')
+        try:
+            tag = client_components_tag("test-rt")
+            # Extract the sexp source from the script tag
+            sexp_source = tag.replace('<script type="text/sexp" data-components>', '').replace('</script>', '')
+            js_html = _js_render('(~test-rt :title "hello")', sexp_source)
+            py_html = py_render(parse('(~test-rt :title "hello")'), _COMPONENT_ENV)
+            assert js_html == py_html
+        finally:
+            _COMPONENT_ENV.pop("~test-rt", None)
+
+
 class TestPythonParity:
     """JS string renderer matches Python renderer output."""